Tunnel-roof shield.



y PATENTBD MAY' 1, 1906.

J. o.. MEEM. TUNNEL R001" SHIELD.

Witnesses:

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PATENTED MAY-1, 1906.7

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UNITED sTATns PATENT onnicn.

, JAMES C. MEEM, OF BROOKLYN, NEW YORILASSIGNOR OF. ONE-HALF BOROUGHACONSTRUCTION COMPANY, OF. BROOKLYN, NEW; YORK, A

V,part of this TUNNEL-ROOF jSHlELD.

' Specification of Letters Patent.

PatentedlVIay 1.,- 1906 i Application filed October 11, 1905.`Seriallilo.,282,299-v v l llo all whom, it may concern.-

Beit known that, I, JAMES C. MEEM, a citi- Zen of the UnitedStates,residing at Brooklyn, iii the countyk of Kings and -,State of.New. York, have invented a new and useful Tunnel-Roof Shield, of whichthefollowing is a specifica--.

tion..

This inventionrelates to tunnel-roof shields,-

and constitutes an improvement upon one of similar character for which Iobtained Letters Patentof. the United States December 9 1 902, e

The objects of the inventionare to obviate unnecessary dredging, toaccelerate they procedurei of settling or positioning the shield,

and to improve its construction..

With the above and other. objects in view,

as Willappeanas thenature of the invention is better understood ,thesame consistsv in the novel constructionand combination ofl parts of atunnel-roofshield, as will be hereinafter fully described andv claimed..

In the accompanying drawings, forming a specification, and in which likecharacters of reference indicate corresponding arts, Figure 1 isa viewi,in end elevation exhi iting theshield of the present inventionpositioned relatively to a tunnel. Fig. 2 isa verticallongitudinalsectional view through the shield and tunnel. Fig. 3 is a.perspective detail view of aportion of one of the shields. Fig. Agis aview `in elevation show-` j ing themanner in which `a shield that is tobe positioned is connected with one that vis already in position.

The shield, whichmay be made of any desired length and on any desiredarc either of a circle or of a conic-section, comprises arch members y1,which will preferably be ofwood and spiked or otherwise suitably securedtogether, upper and lower chord-stiffeners 2 and 3, and uprights 4, thatbear at their respective ends against the opposedfaces of thechord-stiffeners. The parts above named are held assembled and gboundyfirmly' ,together by rods or eye-bars 5, that pass over the arch asbands and underneath as tensionchord members 6 and are retained undersuitable tension by turnbuckles 7, or there may be bands passed over theshield as short detached straps spiked or bolted to the arch, or theremay be chord tension members attached to the lower edges of the shieldby bolts or rivets or in any othery preferred manner, Where they areretained under tension by turnbuckles, as in the illustration. Thesesion-chord. members f `.parts named, and as usual, there may be em:yployed segmental ribs Aor compression meme-...-

Fig. 1, or the shield may vedges 13., as shown at the leftof Fig'. 1.,.i;

As stated,.it is one of theobjects offthezin-.-

maybe carried by draft-,bars 8,theterminals, of which are formed yinto.eyes,9.to engage. similar eyes,10 on the terminalsof. theten..

In :addition to ithe V,6.o

bers 11, constructed, preferably-'fof 4.steeltv .beams spaced apart atsuitable intervals aIld., 'interposed between the archmembersl and.,6.5

uppervchord-stiffeners 2... Againstthe inner.,.v

. faces of the terminals of the ,compression mem-a bersbear.socket.plates 12', inewhichithe. ends of thechord-stiii'eners`3.are seated, lf pre-.il

. ferred,.the lower .edges ofthe,shieldrnayter I7o yminate in thesameplaneas the,.,tensione ;y chord members-6, as shownat the. rightof beextended ibelowf., .y the tension-chord.membersito form ,cutting ventionto obviate unnecessary dredging andy. to facilitate the settling orpositioning of the, shield. vThis is effected by combiningwith .theshieldat spaced intervals anda.adjacer-it,8,04

to its edges. a series ofpipes 14, gproyidediat l their. upper .endswith couplings 15, v.with 5,

which may connectv pipes 16, leading. to a source of water.underpressure or to a suitev .Y able force-pump, the .objectbeingitodrive85 .water underv high pressurethrough thepipes- 14 adjacent to theedgesof theI shield, thus, to effect washing away of the river-.bottomand to facilitate the settlingof the shield.

These shields are intended to be sub- 9.o merged on the bottom of ariver or harborHV and the excavation to be carried on under' neath, theroof of the shield serving to hold any compressed air or keep o ut ,thewaten It is contemplated that .theshield shallbe sunk onto a naturalbottom or to a bottom which at first vhas ybeen dred ed to a sufi-L.cient depth to allow it to be fu ly or partially covered by the naturalbottom when the lat-` ter `has been restoredto its original .level.1,ooAny .projection of the roof ,whichmay be above this level it is intendedto cover by a f mixture of clay to renderthe roof as far as possible airand water tight. A heavy canvas or other cover may be laced over the Io5 joints, if desired, and over this in turn may be placed a blanket ofclay as described elsewhere.

To illustrate a procedure under which the shield of this invention isemployed, one 1ro method is herein outlined. A portion of the bottom ofthe river or harbor may be iirst dredgedA to a suitable depth, afterwhich the l roof or shield which has been constructed and iloated toposition over the dredged bottom is sunk, it being i'irst properlyweighted to cause it to be submergedrby its own weight. As soon as ithas corne to a position on the bottom which is reasonably near itsintended permanent location the pipes 14 are connected with powerfulpumps on a oat in the vicinity, and water is then forced down thesepipes under such heavy pressure that the ground under the edges of theshield is forced away allowing it to sink into the mud. As the shieldsinks to its position a covering of earth is thrown over it to settleitin position and to render it impervious to the compressed air whichmay be used in the subsequent tunneling operations. As soon as the rearend of one section of a shield is in place another is brought out andsunk to position and attached to the forward end of the last section byropes 17, of which there ma be any preferred number employed. T eseropes are passed through oriiices in angleplates or cleats 18, securednear the terminals of the shields, the terminals of the ropes being heldagainst movement relatively to the cleats or angle-plates on the shieldthat is ositioned. As the forward end of the shield is jolted down toposition the ropes may be pulled taut by divers or from above, and assoon as the abutting sections are in place a cover or mattress of canvaswill be thrown over the joint and a cover of clay may be dumped over thewhole. The rear end of the last section and the forward end of thepreceding section may then be washed down by water through the pipes, itbeing understood that the to fastening may act as a hinge and the lowerastenings may contain pulleys or Wheels, by means of which the lowerjaws of the abutting ends may be pulled tight as the forward end iswashed down. This rocedure, however, may be varied by sin ring theentire length of the shield at one time by providing a suiiicient numberof pumps, so that the entire length may be washed to position at oneoperation, or it may still be further varied, so that one section at atime may be washed down to position before a subsequent section isattached. It is also intended that one pump shall operate several of thepipes at one time, or valves may be so Varranged that one or moreof thepipes may be operated to the exclusion of all the rest. In the eventthat a boulder be in the vicinity of one of the pipes and the groundadjacent thereto be soft it will be more necessary to bring the heaviestwater-pressure to bear upon that one in the vicinity of the boulder tocause it to slip to one side or the other, and thus permit thetunnel-shields to settle into place. With the roof-shield in positionand a covering of impervious material over it it will then be an easymatter to sink a shaft at either end of the shields and introducecompressed air and laborers for the excavation and operation of thetunnel, which may then be built by ordinary methods.

Having thus described the invention, what is claimed is 1. A tunnel-roofshield having means combined therewith for introducing Water underpressure beneath its edges, and means for assembling it with an adjacentshield.

2. A tunnel-roof shield having a waterconveying pipe disposed atintervals along two of its edges and provided with means for attachmentto a water-supply, and means for assembling it with an adjacent shield.

3. A tunnel-roof shield having arch menibers, upper and lowerchord-stiffeners, uprights that bear at their respective ends againstthe opposed ends of the chord-stiffeners, means for holding the partsassembled, means for introducing water beneath the edges of the shield,and means for combining it with an adjacent shield.

4. A tunnel-shield having cutting edges, water-conveying pipesprojecting throu h the edges, and means for assembling a shie d that isbeing submerged with one that is already submerged.

5. A tunnel-shield having cutting edges, water-conveying pipesprojecting through the edges, and orificed cleats arranged adjacent tothe ends of the shield and adapted to be engaged by ropes or chains toassemble a shield that is being submerged with one that is alreadysubmerged.

In testimony that I claim the foregoing as my own I -have hereto aiiixedmy signature in the presence of two witnesses.

JAMES C. MEEM,

IOO

